Decomposition of ibuprofen in water via an electrochemical process with nano-sized carbon black-coated carbon cloth as oxygen-permeable cathode integrated with ultrasound

Abstract

The main aim of the present investigation was the treatment of ibuprofen (IBP)-polluted aquatic phase using a novel oxygen-permeable cathode (OPC)-equipped electrochemical process (ECP) integrated with ultrasound (US). According to kinetic modeling, the decomposition rate of IBP by the integrated process was 3.2 × 10−2 min−1 which was significant in comparison with the OPC-equipped ECP (1.4 × 10−2 min−1) and US alone (2.4 × 10−3 min−1). Increasing the current resulted in the enhanced generation of H2O2 and consequently, improved the degradation of IBP in the solution. Excessive concentrations of Na2SO4 as supporting electrolyte led to no significant enhancement in the reactor efficiency. At initial IBP concentration of 1 mg L−1, complete removal of IBP with reaction rate of 1.7 × 10−1 min−1 was happened within a short reaction time of 30 min. The pulse mode of US led to more than 10% increase in the removal efficiency compared with the normal mode. The presence of scavenging compound of methanol caused the highest drop in the efficiency of the integrated treatment process, indicating the substantial role of free hydroxyl radicals in the degradation of IBP. Intermediate byproducts generated in the solution during the decomposition were also identified and interpreted.